plc:S7-200 224cn 觸摸屏:SMART LINE700,采用485通訊,通訊線采用多芯屏蔽線,中間有接頭,計(jì)數(shù)用對(duì)射型光電開(kāi)關(guān),plc控制柜在滑軌上來(lái)回移動(dòng),觸摸屏在固定的柱子上,剛開(kāi)始一段時(shí)間觸摸屏計(jì)數(shù)準(zhǔn)確,顯示正常,用一段時(shí)間后觸摸屏計(jì)數(shù)在某個(gè)時(shí)間段會(huì)出現(xiàn)####,過(guò)一會(huì)就好了,計(jì)數(shù)準(zhǔn)確,求原因?